Observations of a Seasonal Jet-like Circulation at the Central North Sea Cold Pool Margin

In June/July 1996, a survey of the offshore region between the north-east coast of England and the Dogger Bank was undertaken using towed and conventional profiling CTDʹs and satellite tracked drifters. Strong bottom fronts bounded a pool of cold, dense bottom water isolated below the seasonal thermocline. These features extend continuously for ~500 km along the 40 m contour, from the Firth of Forth to the eastern end of the Dogger Bank. Geostrophic current estimates and drifter trajectories demonstrate the existence of persistent and narrow (10-15 km) cores of cyclonic near-surface flow (cold bottom water to the left) with velocities in excess of 0·1 m s-1. The results are consistent with a seasonal baroclinic flow skirting the north east coast of England which provides a direct pathway for material and fish larvae from coastal regions to the northern Dogger Bank and central North Sea.